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Lavrov Cyril

The Facukty of Powerengineering and Automation

Speciality: Hoisting-and-transport machines

Theme of master's work: "Substantiation of time parametrs of a gear shifting of a dual-speed chain conveyor"

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The work author's abstract

The work purpose:

To raise durability of operation of knots of a two-high-speed chain conveyor by means of a substantiation of algorithm of a gear shifting of the two-high-speed conveyor.

Problems of the given work:

1. To receive the mathematical model describing a movement of the working body of a chain conveyor;

2. On the basis of mathematical model to gain optimum time parameters of a gear shifting of a two-high-speed chain conveyor;

3. On the basis of the gained mathematical model of system a chain conveyor - the two-high-speed electric motor it is necessary to prove decrease of dynamic loads on a conveyor flight chain.

Urgency of the given work:

The chain conveyor is the basic transport facility of mined rock in breakage faces of coal mines. Productivity of a section depends on uninterrupted operation of its operation as a whole.

The scraper conveyor, containing the hydroclutch, are not effective enough, they have the restricted functionality. The hydroclutch speed-torque characteristic does not allow to carry out dispersal of traction body of the conveyor with intensity, safety for attendants, and also does not allow to realise decrease of traffic speed of a flight chain for performance of technological operations on delivery of materials. Wear of protection of the hydroclutch is interfaced to the idle time of the conveyor caused by the time on repeated pouring an in it of emulsion, installation of a new meltable stopper.

In the given work the two-high-speed scraper conveyor is observed without equipment by the hydroclutch. Advantages of such two-high-speed scraper conveyors consist in the following:

- Possibility of transportation of accessory materials of the lowest speed;

- Chain conveyors are the basic means of mechanisation of coal delivery from breakage faces; also they are applied on concentrating mills and at surface minings of minerals;

- High efficiency;

Simplicity of an elongation frame;

- Fitness to heavy working conditions;

- Use possibility in a complex with other machines.

The urgency of the given theme consists that at present in the field of two-high-speed chain conveyors are spent very few researches and there are no theoretical developments on transients in a system a chain conveyor - the two-high-speed electric motor without equipment by the hydroclutch.

Scientific novelty

Researches of operating modes of chain conveyors have shown, that they possess a number of essential deficiencies peculiar to in the conveyor system consisting of two noncontrollable electric drives connected among themselves by flight chain. The most essential deficiencies are:

Insufficiently effective levelling of loadings between drives;

- Necessity concerning the big prestressing of a flight chain for prevention of an upturning of scrapers and folding of chain links that raises a flight chain friction on a chute, reduces term of its service and system efficiency as a whole.

Besides the research is having shown, that separate regulating by the chain conveyor electric drives allows not only leveling down loading, but also it is rational to distribute it between drives. At the expense of a rational load dispatching it is possible to reduce force of a tension of a single chain at incomplete loading of the conveyor that raises its efficiency and reduces deterioration of a chain.

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